Lec# 20 Plants and Medicine

I. Medicinal Plants II. Poisonous Plants III. Psychoactive Plants

Disclaimer!

Critical evaluation is extremely important here. I am not making any endorsements nor should you use this information to treat yourself without the consultation of a doctor!

Someone once said there are only two types of fools: one professes “this is old and therefore good” and the other says “This is new and therefore better”

Point: Use your scientific evaluations in the matter, it is a matter of life or death!

I. Medicinal Plants

1. Approximately 25% of today’s prescription drugs come from plant extracts (see Table 1).

2. Only about 15% of the known plant species have been screened for medicinal purposes.

3. Most medicinal plants come from the Tropics.

Medicinal Plants in the Tropics

Most medicinal plants have been identified by the indigenous people by trial and error.

50% of the 250,000 plant species are from the Tropics.

At least 10,000 species in the Tropics have not yet been identified.

NCI - Plant Collection Program (1986-1991) 10,000 plant samples collected for screening

against HIV and cancer 2500 species and 200 families Of the 3000 extracts analyzed, 170 contained

agents active against HIV 776 fully identified species, 106 had active

agents. 62 were previously known as medicinal plants. 44 were entirely new.

1. Medicinal Plants (continued)

4. The most significant medicinal plants used for prescription drugs contain steroids or alkaloids (see Table 1).

1. Medicinal Plants (continued)

5.The rapid destruction of our tropical rainforests threatens the development of potentially useful drugs

Forest Loss Is Severe in the Tropics

0

10

20

30

40

50

Asia Africa Latin America World

1. Medicinal Plants (continued)

6. There are a host of non-prescription plant remedies which have medicinal uses. These are often referred to as “herbal medicines”.

Ginkgo (Ginkgo biloba) Complex of

phytomedicinals from the leaves

Improves blood flow Improves memory in

older people Effective free-radical

scavenger Side effects are

restlessness, diarrhea, nausea and vomiting

Echinacea (Echinacea species)

Extracts from shoot, root and rhizome

Acts as immunostimulant

Speeds up cycle of cold virus and flus

NOT preventative.

Ginseng (Panax ginseng, P. quinquefolium, Elutherococcus senticocus) Mixture of compounds

from root Traditional Chinese

medicine for 5000 years Increases stress

tolerance Speeds up metabolism Anti-carcinogenic No known side-effects

Chamomile (Matricaria recutita and Chamaemelum nobile) Mixture of terpenoids,

coumarins, and flavonoids from dried flower heads

Soothes stomach-aches Anti-inflammatory,

anti-spasmodic and anti-bacterial actions

Mild sedative

Feverfew (Tanacetum parthenium) Sesquiterpenoid

lactones from leaves Used for 2000 years Effective head-ache

treatment, especially migraines

Garli c (Allium sativum)Onion (Allium cepa) Organo-sulfur

compounds from leaves

Anti-carcinogenic and anti-microbial

Anti-atherosclerosis and anti-hypertensive

Toxic in high amounts

Milk Thistle (Silybum marianum)

Complex of flavolignans from seeds

Protects liver against toxins, particularly against poison from Amanitas phalloides

Helps against hepatitis and cirrhosis of the liver

St. John’s Wort (Hypericum perforatum) extract from leaves Effective for

depression and sleeplessness

anti-retroviral activities (AIDS)

Side effects include photosensitivity and dermatitis

Saw Palmetto (Serenoa repens)

from fruits Increases frequency of

urination Treatment for prostate

cancer Protects against edema

(water retention) and inflammation

English Hawthorn (Crataegus laevigata) Leaves, flowers and

fruit can be used Increases dilation of

blood vessels Used for mild forms of

heart disease

Green Tea (Camellia sinensis)

Polyphenols from leaves

anti-cancer inhibiting tumor initiation and cell proliferation

anti-oxidant

Wine Grape (Vitis vinifera) Contains over 50 different

flavonoid phenolics including resveratrol and catechins

Reduces heart disease by inhibiting platelet aggregation, lowering LDL (low density lipoproteins) and acting as antioxidants

White Wine vs. Red Wine Phenolics(mg/L) White Wine Red Wine

Total Phenolics 200-300 1500-3000

Hydroxycinnamates 50-200 25-150

Anthocyanins 0 600-1000

Catechins 10-50 60-150

Flavonols Negligible 25-250

Licorice (Glycyrrhiza spp.)

Phenolic compounds from the root or rhizome

anti-oxidant anti-tumor anti-inflammatory

Ginger (Zingiber officinale)

from the rhizome Over 12 compounds

with anti-oxidant activities greater than vitamin E

anti-tumor anti-emetic (inhibits

vomiting)

Soybeans (Glycine max) Contains phytoestrogens like isoflavones Reduces health risks associated with menopause:

osteoporosis and heart disease in women Reduces prostrate, colon and breast cancer

Vegetables

Vitamin A, C and E anti-oxidant anti-cancer

Take Home Message

Many plants with medicinal qualities Often a synergistic effect of different

compounds No magic bullet